The present invention relates to a carrier recovery circuit for recovering the carrier of a PSK (phase shift keying) signal employed in time division multiple access (TDMA) communication systems.
In a prior art carrier recovery circuit for recovering the carrier of a received PSK modulated signal, a carrier component is extracted from the received signal and converted to a lower frequency. The extracted carrier is bandwidth and amplitude limited by a narrow pass-band filter and an amplitude limiter to eliminate unwanted signals and amplitude fluctuations and is reconverted to the original frequency for application to a PSK demodulator as a reference carrier through a phase shifter. A phase comparator detects a phase difference between the input and output of the bandwidth and amplitude limiters and controls a voltage controlled oscillator which generates the variable frequency signal necessary for the frequency conversion and reconversion. However, due to slow response characteristic, the prior art carrier recovery circuit is not capable of responding to interburst frequency variations, resulting in an increase in bit error rate.